Armchair



FIG. 1 is a front perspective view of an armchair showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is right side view thereof, the left side being a mirror image thereof;

FIG. 4 is a rear elevational view thereof; and,

FIG. 5 is a top plan view thereof. 

The ornamental design for an armchair, as shown and described. 